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THE 

AMERICAN NATURALIST. 

Vol. XXII. FEBRUARY, 1888. No. 254. 

ON METEORITES. 1 

BY DR. HANS EEUSC'H. 

TI7"E know that in the organic world, besides the larger animals 
'* and plants, there exist immense numbers of living beings of 
diminutive size, from those barely visible to the unaided eye down 
to those which can only be discerned in powerful microscopes, and 
of which many thousands live in a space no larger than a drop of 
water. Similar is the case with the heavenly orbs revolving in the 
infinite space. Besides the big luminaries, numerous swarms of 
very small bodies are hurrying through the space in their different 
varying orbits. To the smallest of these — the so-called meteorites 
— I here wish to call your attention. There is a circumstance 
which imparts them with a special interest to us ; for they some- 
times fall to the earth, so that we are able to lay hold of them, 
touch them with our hands, study them chemically and microscopi- 
cally — in short, examine them by all the means available to us for 
a scientific investigation of their nature. The meteorites thus form 
a kind of connecting link between astronomy and mineralogy — 
sciences otherwise rather distant, but which in this instance are 
brought to mutually throw light upon each other. 

It is probable that, on an average, several meteorites reach the 
earth every day, but many falls occur at night, while others drop 
into the sea, are lost in deserts or in places inhabited by ignorant 
people. In going over the falls of meteorites which have come to 
our knowledge, it appears that no more than four or five cases a 

1 A lecture delivered at the University of Christiania, Norway. 



98 On Meteorites. 

year, on an average, are recorded ; and in but comparatively few 
instances the fallen stones are hunted up by people in order that 
they may become of use to science. The meteorites, therefore, 
owing to their variety, rank among the most precious treasures of 
the mineralogical museums. To illustrate the value generally 
attached to them, it may be mentioned that after it had become 
known that the meteorite found last year at Tysnses, Western Nor- 
way, had been acquired by the Christiania Museum, a mineralogist 
was dispatched by the Riks-museum, in Stockholm, Sweden, the 
long way across the Scandinavian Peninsula, in the hope that he 
might be able to pick up some fragments. 

A chief object of this paper is, therefore, to call the attention of 
the public to the meteorites, in order to prevent possible falls from 
being passed unheeded. The attention once aroused, it may also be 
possible to ferret out meteorites, the fall of which, in former times, 
has been kept a secret, owing to the superstition that, reduced to 
a powder, they might serve as a medicine for man and beast. In 
Norway, for instance, they were known as "thorelo" — i.e., "lo," 
or wadding of Thor, or thunder — the belief being that they fell 
during thunderstorms. Not all the stones which have been pre- 
served as "thorelo," however, are meteorites by any means, many 
of them being only common pebbles, pieces of pyrites, or some other 
kind of mineral. 

After these preliminary remarks, I shall proceed to the special 
subject of this paper — the meteorites and their nature — to be treated 
of in three separate sections, viz. : — 

(1) The phenomena accompanying the fall of meteorites ; (2) 
Their mineralogical nature, and (3) Their position as celestial 
bodies. 

The circumstances under which the fall of meteorites occur being 
rather similar in most instances, we may take, for an example, the 
fall of the Tysnses meteorite. It occurred on the 20th of Maj r , 
1886, near the farm called Midt Vaage, situated on the Island of 
Tysnres, south of Bergen, Norway. Between eight and nine 
o'clock in the evening the inhabitants in a wide circle of surround- 
ing country were frightened by a loud report, which most of them 
took for a clap of thunder, the stone falling down immediately after 
the report. I have myself examined two grown-up persons who 
witnessed the meteorite coming down from the air. One was a 
woman working in a potato-field. She heard a loud noise, and, 



On Meteorites. 99 

looking up into the sky, observed a black mass of clouds, from 

which she thought she heard a cracking sound, repeated five or six 

times, upon which the stone fell with a whizzing and rumbling 

noise a little distance off. Dust arose from the spot where it struck 

the ground. The woman walked up to where it fell and saw a hole 

in the ground, but found nothing else, as the meteorite had bounded 

off several yards from where it first struck. The other eye-witness 

■ — a man who was a little further off — was just going home after 

having finished his day's work. He heard the report, and shortly 

after saw the stone coming down, " like a shot bird." No fiery 

display was noticed at the place ; but people who witnessed the 

phenomenon from a distance of several miles (a Norwegian mile 

about equals seven English miles) — as, for instance, in Bergen and 

in Vossevangen — observed a fire-ball darting with great speed 

across the sky and then exploding in the direction of Tysnses. 

Comparing the accounts of the direction of the fire-ball by the 

different observers, it appears that the meteor must have moved 

nearly vertically towards the earth's surface. That the fire-ball 

escaped the notice of those on the spot may be accounted for by its 

being right above their heads, as one seldom notices what occurs 

right over one's head. Their attention was first attracted by the 

report ; but as this, of course, was heard a considerable time after 

the explosion of the fire-ball, the fiery display had ceased long 

before the thundering noise could reach them, after which some 

time again elapsed before the stone fell. The man pointed out to 

me the corner of the field where he was standing at the time he 

heard the report; when the stone fell he had nearly reached his 

house. In ascertaining the distance, he found that it took him about 

one minute and ten seconds to walk from one place to the other. 

Judging from the space of time which elapsed between the report 

and the fall, the explosion must have taken place at a very great 

height above the surface of the earth. With due regard to the 

traveling speed of the sound and the probable celerity of the fall, 

the height may be estimated at twenty to thirty thousand metres ; but 

any certainty cannot be arrived at. 

The next morning a girl living close by found a big, black 
stone lying in the grass. She put it aside, but did not mind it any 
further ; and people's attention was not called to it before it was 
rumored that a stone had been seen falling from heaven. The fol- 
lowing Sunday the curious stone formed the main topic of 



100 On Meteorites. 

conversation among the people assembled at church. An emigrant 
Norwegian, on a visit home from America and about to return to 
this country, made a bargain with the poor woman on whose land 
the stone was found : he was to take it away for a mere song ; and 
the Tysnses meteorite came thus very near going to America. On 
coming home, however, the woman became uneasy at the idea of 
selling such a God-send — direct from heaven — and she returned the 
money. Shortly after, the district physician, Mr. Gjestland, heard 
of the stone, and, realizing its great scientific value, he at once took 
it into his charge. It is owing to this gentleman's most obliging 
intervention that the stone — against a handsome remuneration, of 
course — was secured for the University of Christiania. This 
meteorjte weighs about forty pounds. Several smaller fragments 
were also found. 

The phenomena mentioned above — viz. : a fire-ball rushing along 
and exploding with a thunder-like report, followed by the coming 
down of the fragments — are those regularly observed accompanying 
the fall of meteorites. In some cases the velocity of the fire-ball has- 
been ascertained to be sixty to seventy kilometres a second. This 
tremendous velocity accounts for the fire phenomenon, as the atmos- 
phere, not being able to escape before the missile, becomes conden- 
sed to an enormous degree — a great quantity of heat thus being 
developed, according to the known physical laws. The meteorites, 
at one time having the temperature of space through which they 
were rushing — a temperature far below the freezing point — will thus 
become enormously heated on the outside when entering the earth's 
atmosphere. The pressure of the strongly-condensed atmosphere,, 
finally exceeding a certain limit, acts as a blasting-agency, according 
to a commonly-accepted opinion, and the fire-ball explodes. The 
fragments are still glowing for a while after the explosion, but, as 
a rule, they have probably become cooled off when reaching the 
ground. Nor is the final speed very considerable, the original 
velocity of the fire-ball having been diminished by the resistance of 
the air. 

When falling at full speed, the surface- of the meteorites may be 
supposed to be continually melting — nay, perhaps, evaporating. 
By the friction of the air, however, the molten substance is removed 
almost as fast as it is formed. In this way the "fire-tail " — which 
the observers in many cases affirm having seen — may be explained. 
In the same manner the " smoke " is formed which, on several occa- 



On Meteorites. 101 

sions, has been observed floating in the wake of the fire-ball, after 
the latter has disappeared. Several people assert that such a smoke 
was also seen accompanying the Tysnaes meteorite. The fallen 




Fig. 1. The Tysnees Meteorite. 

stones show various signs of intense heating in the atmosphere, to 
which we want to direct the attention. In some cases, when stones 
have been taken up shortly after striking the ground, they have 
still been warm. In one instance it has been related that the fallen 
stone was at first so hot as to burn the fingers, and afterwards turned 
so cold that it could not be held in the hand for that reason. This 
may be regarded as very probable, when we consider that the heat- 
ing in the atmosphere only lasts a few seconds, and that its action, 
consequently, must be quite superficial. Space, on the other hand, 
has an exceedingly low temperature, and the freezing coldness of 
the interior of the stone will therefore soon lower the temperature 
of the surface. 

The interior of the meteoric stones, as a rule, is gray or whitish ; 
the exterior, on the contrary, is covered with a blackish crust, which, 
on examination, proves to be the stony substance, having undergone 
a melting process. It is difficult to tell what shape the meteorites 
have before entering our atmosphere, as we only gather bits and 
fragments after the explosion. These show the effect of the com- 
pressed and intensely-heated air. The edges of the fragments, 
originally sharp, have become rounded, and on the surface there 
appear deepened marks, many of which look as if the stone had 



102 On Meteorites. 

once been soft as a dough in which the kneading-fingers had left 
their impressions. The air has had a consuming effect on the stone- 
— much in the same way as a powerful jet of sand acts on a solid 
body. Mr. Daubree has experimentally imitated this remarkable 
effect of the air. Not being able to move a solid against an aeri- 
form body with sufficient speed — as is the case with the meteorites 
— he chose to proceed in the opposite way, making air strike solid 
bodies with great vehemence by exploding dynamite cartridges 
against an iron rail. The result of the experiment showed that the 
gases, suddenly developed by the dynamite exploding, produced 
hollows even in a body of such resi sting-power as an iron rail, and 
the form of the impressions — in this as well as in his other 
experiments — corresponds exactly to those found in the meteorites. 

Having now considered the phenomena accompanying the fall of 
meteorites, we shall now direct our attention to their mineralogical 
nature. 

The meteorites maybe classed in two primary groups : stone- 
meteorites — to which belongs the Tyshses meteorite — and iron- 
meteorites, which consist chiefly of this metal. The two principal 
minerals composing the stone-meteorites are eustatite and olivine (or 
chrysolite)— both of which are also found on our globe, though rather 
rare — besides which these meteorites also contain grains of native 
iron, as an occasional sprinkling, through the mass. Examined by 
the microscope, they exhibit a structure which proves that origin- 
ally and before entering the atmosphere they were formed out of 
melted masses by congelation. Fouque" and Michel LeVy have 
produced, artificially, the structures mentioned by melting together 
suitable substances. It thus appears that these small heavenly 
bodies, in precisely the same manner as the crustof our own globe, 
consist of originally molten masses, having afterwards become sol- 
idified. In this connection, it may not be out of place to remind one 
of the fact that the interior of the earth consists of substances heavier 
than those most commonly found on the surface. The meteorite is 
also heavier than common stone ; and it has been conjectured (with 
several reasons to support this hypothesis) that the interior of the 
earth consists of a substance similar to that composing the 
meteorites. 

On further examining the meteorites, it is found that after having 
passed through the original congealing process they have undergone 
several changes on their way through space. In many cases it is 



On Meteorites. 



103 




mm 




--7S 



Fig. 2. Braccious structure of the 
Tysnees meteorite. Drawn by the 
author. 



evident that their substance has been broken into small pieces, which 
again have become cemented together — a structure seen with un- 
common distinctness in the Tysnres meteorite, as represented in the 
accompanying cut (Fig. 2). Not all 
the fragments are so large as to be 
seen by the unaided eye ; for in ex- 
amining the stone by the microscope 
some very small ones are also found, 
mostly of a round or globular form. 
This breaking up and putting 
together again seems in the case of 
the Tysnses meteorite to have oc- 
curred at least twice. 

The large fragments seen, in Fig. 
2 are composed of smaller ones, it 
being a case similar to a conglomerate 
in which the individual roll-stones 
consist of conglomerate. Fig. 3 
shows a portion of the Tysnses 
meteorite viewed in the microscope ; while Fig. 4 represents 
an isolated globule of olivine, greatly magnified. It contains 
a brownish and glassy substance, in form reminding one of the cells 
of plants. Similar formations, not rare in meteorites, have furnished 
a fanciful scientist an excuse for obstinately asserting that they 
actually are the remains of plants. It is to be regretted that such 
is not the case ; for it would undoubtedly have been interesting if 
in this way we had been able to lay hand on specimens of organic 
life from other globes. 

The second group of meteorites consist of native iron — as men- 
tioned above — with an occasional sprinkling of grains of stony 
minerals. Native iron occurs but rarely on this globe, as ir.on 
readily enters into combination with oxygen — in other words, it 
oxidizes, or rusts. In fact, it is so rare in nature, except in the 
meteorites, that any lump of iron produced by man was formerly 
believed to have fallen down from heaven. This was also Norden- 
skiold's impression when, some years ago, he found quite a quantity 
of native iron in Greenland. The find was at that time much talked 
of; but Steenstrup afterwards pointed out that the supposed meteor- 
ites were only big lumps of iron which had weathered out of the 
rock on which they were found. This rock abounded to a remark- 
able degree in iron. 



104 



On Meteorites. 



The iron of the meteorites, as a rule, contains more or less nickel 
irregularly distributed through the mass. If the polished surface 
of the meteoric iron be exposed to the action of some acid, there will 
appear peculiar linear designs, called the " Wiedmannstatten figures" 

(after the discoverer), the 
acid attacking the iron 
containing nickel to a less 
degree than the pure 
metal. 

We will now direct our 
attention to our third sub- 
ject, and consider the 
meteorites as celestial bod- 
ies. 

Before entering into this, 
it will be necessary, how- 
ever, to say a few words 
in regard to shooting-stars 
and comets, these being 
the celestial phenomena 
with which the meteor- 
ites are most nearly com- 
parable. 

To a common observer, 
who does not make a spe- 
cial study of the heavenly 
vault, it looks as if the 
shooting-stars move quite 
irregularly — now in this direction, noAV in another. If, however, 
their courses be carefully traced on an astronomical chart, it will be 
found that in most cases they radiate from certain points in the sky 
— a great many of which have already been ascertained. That the 
shooting-stars come from a certain point means that they are moving 
from that section of space towards the earth, the radiation being 
only the effect of the perspective as they move from the distance in 
the direction of the observer. The best-known swarm of shooting- 
stars is undoubtedly the one which appears to radiate from the 
constellation of the Lion, and is passed by the earth on the 1 3th of 
November. As on this day extremely numerous falls of stars have 
been observed, with a regular interval of thirty-three years, it is 




Fig. 3. Portion of the Tysnses meteorite, mag- 
nified 65 times. Globules composed of enstatlte 
crystals; the cementing substance in the upper 
globule is a brownish glass. &, grain of olivine 
Drawn by the author. 



On Meteorites. 



105 



evident that they belong to a swarm which, after a revolution of 
thirty-three years around the sun, returns to the orbit of our globe. 
The comets are apparently something entirely different from the 
shooting-stars ; for while the latter are quite small and only appear 
within the terrestrial atmosphere, the comets are bodies of immensely 
greater size,comparatively speak- 



ing, and moving at a very great 'J~- \ -.v.; 
Investigation shows, however, .M/'' 



distance from our little planet. Pr^6 




that the orbits of both comets 
and shooting-stars have the same 
form, they being elongated c6nic 
sections : hence their approaching 
from distant dark regions of 
space — now close to the sun, now 
again retiring to an immense 
distance from it. In regard to 
one comet, it has, furthermore, 
been ascertained that it moves in 
the same orbit as the swarm of 

shooting-stars mentioned above. fa^Magnmedi^ u^'vrlwnlXl 
The exact nature of the comets au 

has not yet been made out with any certainty, the best-sup- 
ported hypothesis being that they consist of immense quan- 
tities of small solid bodies. The comets nearest to the sun, when 
tn their greatest proximity to that body, are exposed to an enor- 
mous heat, soon followed, as they retire, by a cooling off equally 
enormous. The strong influence of the sun's vicinity on the comets 
shows itself, among other things, in the well-known long tail, which 
they project on the further side from the sun, and the nature and 
origin of which is still rather mysterious. Neither is the true 
nature of the shooting-stars fully ascertained. Many of them, 
however, appear to be small solid bodies rushing through the air ; 
and there are a great many intermediate forms between the common 
shooting-stars and the big fire-balls which explode with a thunder- 
like report and emit meteoric stones. J 

1 Mr. Sophus Tromholt, the author of the beautiful work, Under the 
Bays of Aurora Borealis, has sent me the following interesting 
record of a shooting-star : — 

" One starlight but moonless Saturday night during November or 



106 On Meteorites. 

In the meteorites we have, as seen, at last something palpable 
which we tfre able to study. It will therefore be of great interest 
to have their connection with the shooting-stars and comets more 
definitely established. The study of the orbits of the meteorites, 
however, is rendered much more difficult than that of the shooting- 
stars by their comparatively much rarer and more unexpected 
occurrence, by the terrifying phenomena often accompanying them, 
and by the fact that they are seldom observed by others than 
ignorant people. The mode of studying the orbits of the meteor- 
ites must, therefore, be different from that suited to the case of the 
shooting-stars. > 

Having made a special study of the dates of the recorded falls of 
meteorites, I have come to the conclusidti that they, or at least some 
of them, may be referred to certain systems like the shooting-stars, 
and that in some cases periods^— suggesting a connection with a 
certain group of comets — may be set down with some probability. 

The orbit of the earth around the sun may be considered as 
divided into three hundred and sixty-five parts, one of which is 
traversed on each day of the year. That the fall of a meteorite 
occurs on a certain date means, then, that, the part of the earth's 

December, 1883, between eightand nine o'clock, as Mr. Lionses, a boob> 
seller in Fredrikstad, Norway, was standing in his yard looking inci- 
dentally up into the sky, he observed a shooting-star in the north, at a 
height of about 60°, moving in a curve and gradually increasing a little 
in size. The exact length of time he is unable to state : be had turned 
his eyes away, when suddenly a small, shining body fell down before 
his feet, not two yards off, passiug him so closely that in his fright he 
sprang aside. When the meteor struck the ground sparks flew in all 
directions, and a faint report was heard. This noise was also heard by 
his daughter, who at the time was in the passage leading to the yard. 
Shortly after — 'about a minute '—both father and daughter observed a 
similar meteor in the same direction, which seemed to descend behind 
a neighboring house. 

" The gentleman mentioned is uncertain as to the exact date of the 
observation ; but the choice seems to lie between the Saturdays, Novem- 
ber 3d, November 23d, and December 1st ; but as, according to the 
meteorological observations recorded at the Fredrikstad Station, the 
sky was overcast on the two former Saturdays, the fall must have taken 
place on December 1st, when the weather was rather clear. He has 
stated to me that the size of the shining body was comparable to that of 
a walnut, and the little fragments into which it was broken when strik- 
ing the ground he compared to small beads. Unfortunately, he omitted: 
to collect them, and later search was unavailing, as the yard had been 
swept several times afterwards." 



On Meteorites. 107 

orbit designated by this date is intersected by the orbit of the 
meteorite. It now often happens that the earth is struck by meteorites 
on the same date during two or several consecutive years. This can 
only be explained by the earth on that date passing through a swarm of 
meteorites, or, rather, through a long stream taking several years 
in passing — if we consider that, on an average, no more than four 
falls of meteorites are recorded yearly. Thus, the earth was hit 
four times by meteorites on the 13th of December, between the 
years 1795 and 1813. 1 Since then the earth has not collided with 
any meteorites on that date. 

Still more remarkable than dates which, like the above, show 
the meteorites to go in flocks, are others from which, with a con- 
siderable degree of probability, we may infer a certain period. Thus, 
the 13th of October is a date worth mentioning, as on that day falls 
of meteorites occurred in 1787, 1819, 1838, 1852 and 1872. On 
examining the differences between these years, they will be found 
to be very nearly multiples of 6J — viz. : 5x6J, 3x6J and 2x6|-. 
These falls, consequently, seem to belong to the same flock, with a 
period of between six and seven years. The flock must be rather 
lengthened and takes a considerable time to pass, since the earth 
passes it so often, as is recorded in this case. If the stream be short, 
there is, of course, very little change of the earth being just in the 
point in which the orbits of the earth and the meteorites cross each 
other every time the stream is passing. This would only be the 
case if the period were exactly one or more whole years. As this, 
of course, occurs but very seldom, it is not to be expected that the 
differences between the years be exactly multiples of the periods. 

It may be well to quote other similar periods of meteorites. • In 
February, two series of falls are particularly notable, viz. : — 



February 19, 1785, at Witmess. 
" 18, 1815, at Duralla. 
" 16, 1876, at Indesgherry. 



February 19, 1796, at Tasquinha. 
" 18, 1824, at Irkutsk. 
" 16, 1883, at Alflanella. 



The possibility here suggests itself that the earth on February 
19, 1785, met a flock of meteorites which, with a period of about 
thirty years, reappeared in 1815. No fall is on record from the 
next meeting. From the one then to follow, however — that is, 
from the one to take place sixty-one years from 1815 — viz., in 1876, 
a fall is recorded. It will be observed that the dates are receding, 

1 To these falls may be added a fifth, which occurred on the Western 
Hemisphere, December 14, 1807. 



108 



On Meteorites. 



as the first fell on the 19th ; the second, on the 18th. The third 
fall, if it took place, probably occurred on the 17th; while the 
fourth happened on the 16th. This regular receding of the dates 
may be explained without difficulty as due to the precession retro- 
grading comparatively fast. The case of the three falls of the 
second column may be the same, though their period must be 
shorter, the difference between 1796 and 1824 being 28, and that 
between 1824 and 1883 being 59. 

We give below a list of other systems, in regard to which we 
remark that the figures in parentheses indicate the differences 
between the contiguous years: — 



Period — Between 

six and seven 

.years. 



May 9— Drake Creek 1827 

" 8— Monte Milone 1846 - )Z> 

" 8— Dyalpur 1872~~ (26 > 

" 10— Estherville 1879 - ( ~> 



Period — Between 

six and seven 

years. 



May 11 — Oesel -i 

' ' 12 — Bremewoerde J ' 
" 13— Butsura i 

" 14— Canelles} 

" 12— Kursk •> 

" 14— Nash County / * 



.1855 



1861 



-(6) 
•(13) 



.1874 



This latter system is perhaps a double one, as in the same year 
two falls occur at an interval of a day. 



Period — Be- 
tween six 
and seven 
years. 



March 15 — St. liltienne de Lolm and Valence.. .1806 

" 14-Cutro m3, ~nll 

" 15— Lugano 1826 ^ 

" 16— Rutlam 1863 )° 7 > 

" 14— Middlesborough 1881 (18) 



Period— About 

six 

years. 



August 10— Slobodka 1818, 23 , 

" 10-Iwan 1841_^J 

" 11— Bentham 18o9_^ J 

" 12— Dundrum 1865 



Period — About 
seven 

years. 



July 3— Mixburg 1725_ (2g . 

" 3— Plan 1753 



4— East Norton 1803 

4— Crawford 1859 



-(50) 
-(56) 



Period — 

Eight years. 



-Dogowola 1864 , g, 

-Tennasilm ....1872 



June 26- 

" 28 — leiuiasiiiu ioii , p\ 

" 30— Nogoya 1880 



On Meteorites. 109 

■o . , f September 5— Agen 1814 ,. ftN 

Penod- „ 5 _ Fehrbellin 1854 ~ 40 

Eight years. 1 „ 5 _ Dandapur 1878~ (24) 



Period — 
Nine years. 



September 10 — Limerick 1813 . q . 

10— Carlstadt 1822_| l\ 

" 9— Wessely 1831 



In November there are several falls, suggesting periods of ten 
years, viz.: — 

November 5 — Bourbon, Vendee 1841 .,,,. 

5— Nulles 1851 ' 

November 11 — Lowell 1846 .-.^ 

" 12— Trenzano 1856 

November 29 — Coeenza 1820 ,„». 

" 30— Shalka 1850 ( > 

November 30— Futteb. pore 1822_, 2 q\ 

" 30— Myhee Caunta 1842 ( ' 

In the following series the five last observations correspond to a 
period of about twelve years : — 

May 19— Novgorod 1421 „„.. 

" 19— Schleussingen 1552_; 14 J 

" 18— Walringen 1698 -n08) 

" 17— Hampshire 1806_( 24) 

" 17— Perth 1830J 25 : 

" 17— Igast 1855 l ' 

The oldest date is uncertain, 131 being one less than 11x12. 
Suppose the period being only one-half as long as indicated above, 
still another date might be added — viz. : May 18, 1860, on which 
day a fall occurred at London. 

In the following system, which has a period of about twenty- 
three years, the dates are receding : — 

August 6— Dortrecht 1650 -162) 

" 5— Chantonnay 1812_) ' 

" 4 — Cirencester 1835, 47 - 

" 2— Pawlowka 1882~^ 

As a result, then, several flocks of meteorites can be pointed out,, 
which have a certain period, the latter being, in most cases, between 
six and eight years. It is noteworthy, in this connection, that the 



110 On Meteorites. 

period of most of the comets, the return of which have been ob- 
served, is five or six years. The study of the dates of the different 
falls, therefore, not only suggests that at least a part of the meteor- 
ites move in orbits round the sun, but also intimates a certain rela- 
tion of some of them with a definite group of celestial bodies — viz. : 
the comets of short periods. We have thus established a new link 
connecting the meteorites with the comets in addition to those 
already known — viz. : the strong resemblance of the fire-balls to 
the shooting-stars, as well as the great velocity of several of the 
former, making it probable that they move in orbits of the same 
lengthened form as the comets. If called upon to define the nature 
of a meteorite, briefly and somewhat boldly, I should say, with Mr. 
Newton, the American : A meteorite is a bit of a comet. 

Let me add a few remarks in regard to the question whether there 
is anything in the structure of the meteorites which goes to confirm 
the views here set forth. The orbits of the meteorites being similar 
to those of the comets, the consequence would be, as mentioned 
above, that during a comparatively short, time, once in each period, 
when near the sun, they would be exposed to an enormous heat, 
succeeded by quite as enormous a cooling off in the cold parts of 
space. The fragmentary (chondrite) structure, so general in the 
stony meteorites, is perhaps to be explained in this way. On the 
earth the annual and daily heating and cooling produces, as we all 
well know, the weathering or general crumbling of the earth's crust, 
the formation of stones, gravel, sand and dust. There is a difference 
in regard to the meteorites, in so far as they are not covered with 
water or surrounded by an atmosphere, by which agencies the 
weathering of our earth is brought about; but, on the other hand, 
the difference between the heat and the cold, owing to this very 
want, and especially to the form of the orbit, must be enormously 
greater on the meteorites; for while the differences of temperature 
on the earth rarely rise to 50° C, the changes which take place on 
the meteorites must be estimated at 1,000° C, or more. It may 
not, then, be unreasonably supposed that the fragmentary struc- 
ture so common in the stony meteorites is due to the changes of 
temperature they have undergone. How the fragments may have 
become rounded off by being ground against each other or in 
some other way, may easily be conceived, as there are plenty of 
instances in regard to comets, in which movements in their mass 
have been observed. Theoretically, the study of the Tysnses mete- 



On Meteorites. Ill 

orite is interesting, not only for the fact that it clearly shows the 
chondrite structure to be of a fragmentary nature, but especially 
because it affords proof of the process having been repeated — a cir- 
cumstance not at all surprising in a celestial body which, in its 
wanderings through space, has repeatedly approached close to the 
sun. 

In addition to the above, it should also be remembered that the 
gases— carbonic acid, carbonic oxide and hydrogen — which have 
been successfully extracted from meteorites, are said to give the same 
spectroscopical lines as the comets when approaching the sun. 

The above explanation of the different peculiarities in the struc- 
ture of the meteorites is advanced here, of course, chiefly to instigate 
further investigation. As here propounded, it does away with all 
moments which may not be reasonably admitted in regard to the 
orbits of these celestial bodies, thus, for instance, making unneces- 
sary any recourse to volcanic or other processes supposed to have 
taken place on distant globes once large, but long since exploded. 

In support of this latter theory — viz.: that the meteorites have 
originally belonged to globes of considerable dimensions — it has 
been argued that the formation of so large crystals as are found in 
some iron meteorites can only have taken place on a celestial bodv 
of respectable size. The correctness of this inference may well be 
doubted. It is true that on our earth — which, in this connection, 
may be regarded a big globe — some minerals form large crystals 
during a slow growth ; but it cannot be inferred from this fact that 
large crystals cannot appear on a very small one. The mere circum- 
stance that in the latter the force of gravity is practically nil makes 
matters there stand quite differently from what they are on a great 
celestial body. It may be supposed that as the force of gravity 
plays only an insignificant part, those other forces which produce 
the arrangement of the molecules in the crystals are allowed to have 
their play much more freely than under other circumstances. The 
smallness of the meteoric masses may perhaps also account for their 
easy crumbling and the dislocation of the fragments. The minerals 
of the meteorites, which on our globe appear to belong to the com- 
paratively heavy substances, may in a certain sense be said to weigh 
nothing as long as they form part of a celestial body perhaps not 
a yard in diameter. 

Among other things, it may also be supposed that the electric 
forces called into activity by the violent changes of temperature 



112 



On Meteorites. 



play a much greater rdle than we might be apt to imagine, judging 
from the processes which take place on our earth. 

Finally, I may mention that in some meteorites there is found 
evidence of their having been exposed to an enormous heat after 
their original formation. Several meteorites — particularly one 
from Steelldal, Sweden, which I have examined myself — show traces 
of an inner melting which must have taken place somewhere in 
space before entering our atmosphere, and which has nothing to do 
with the ignition of their surface in the latter and the molten crust 




Fig. 5. The Steelldal meteorite viewed in microscope. ¥ 
by the author. 



Drawn 



thus produced. The appended cut (Fig. 5) shows a portion of the 
Staelldal meteorite sixty-five times magnified. The black parts are 
iron ; the light ones are pieces of unmolten substance swimming in 
a brownish glass, the chemical composition of which is like that of 
the unmolten substance. It will thus be seen that in the structure 
of some meteorites we have a direct proof of their orbits being of 
the same striking form as those of the comets, which alternately 
approach close to the sun and then again recede far from it.